xref: /freebsd/sys/riscv/riscv/minidump_machdep.c (revision c697fb7f)
1 /*-
2  * Copyright (c) 2006 Peter Wemm
3  * Copyright (c) 2015 The FreeBSD Foundation
4  * All rights reserved.
5  * Copyright (c) 2019 Mitchell Horne
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_watchdog.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/conf.h>
37 #include <sys/cons.h>
38 #include <sys/kernel.h>
39 #include <sys/kerneldump.h>
40 #include <sys/msgbuf.h>
41 #include <sys/watchdog.h>
42 #include <sys/vmmeter.h>
43 
44 #include <vm/vm.h>
45 #include <vm/vm_param.h>
46 #include <vm/vm_page.h>
47 #include <vm/vm_phys.h>
48 #include <vm/pmap.h>
49 
50 #include <machine/atomic.h>
51 #include <machine/elf.h>
52 #include <machine/md_var.h>
53 #include <machine/minidump.h>
54 
55 CTASSERT(sizeof(struct kerneldumpheader) == 512);
56 CTASSERT(sizeof(*vm_page_dump) == 8);
57 
58 uint64_t *vm_page_dump;
59 int vm_page_dump_size;
60 
61 static struct kerneldumpheader kdh;
62 
63 /* Handle chunked writes. */
64 static size_t fragsz;
65 static void *dump_va;
66 static size_t counter, progress, dumpsize;
67 
68 static uint64_t tmpbuffer[PAGE_SIZE / sizeof(uint64_t)];
69 
70 static struct {
71 	int min_per;
72 	int max_per;
73 	int visited;
74 } progress_track[10] = {
75 	{  0,  10, 0},
76 	{ 10,  20, 0},
77 	{ 20,  30, 0},
78 	{ 30,  40, 0},
79 	{ 40,  50, 0},
80 	{ 50,  60, 0},
81 	{ 60,  70, 0},
82 	{ 70,  80, 0},
83 	{ 80,  90, 0},
84 	{ 90, 100, 0}
85 };
86 
87 static void
88 report_progress(size_t progress, size_t dumpsize)
89 {
90 	int sofar, i;
91 
92 	sofar = 100 - ((progress * 100) / dumpsize);
93 	for (i = 0; i < nitems(progress_track); i++) {
94 		if (sofar < progress_track[i].min_per ||
95 		    sofar > progress_track[i].max_per)
96 			continue;
97 		if (progress_track[i].visited)
98 			return;
99 		progress_track[i].visited = 1;
100 		printf("..%d%%", sofar);
101 		return;
102 	}
103 }
104 
105 static bool
106 is_dumpable(vm_paddr_t pa)
107 {
108 	vm_page_t m;
109 	int i;
110 
111 	if ((m = vm_phys_paddr_to_vm_page(pa)) != NULL)
112 		return ((m->flags & PG_NODUMP) == 0);
113 
114 	for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i += 2) {
115 		if (pa >= dump_avail[i] && pa < dump_avail[i + 1])
116 			return (true);
117 	}
118 	return (false);
119 }
120 
121 static int
122 blk_flush(struct dumperinfo *di)
123 {
124 	int error;
125 
126 	if (fragsz == 0)
127 		return (0);
128 
129 	error = dump_append(di, dump_va, 0, fragsz);
130 	fragsz = 0;
131 	return (error);
132 }
133 
134 /*
135  * Write a block of data to the dump file.
136  *
137  * Caller can provide data through a pointer or by specifying its
138  * physical address.
139  *
140  * XXX writes using pa should be no larger than PAGE_SIZE.
141  */
142 static int
143 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
144 {
145 	size_t len;
146 	int error, c;
147 	u_int maxdumpsz;
148 
149 	maxdumpsz = min(di->maxiosize, MAXDUMPPGS * PAGE_SIZE);
150 	if (maxdumpsz == 0)	/* seatbelt */
151 		maxdumpsz = PAGE_SIZE;
152 	error = 0;
153 	if ((sz % PAGE_SIZE) != 0) {
154 		printf("size not page aligned\n");
155 		return (EINVAL);
156 	}
157 	if (ptr != NULL && pa != 0) {
158 		printf("cant have both va and pa!\n");
159 		return (EINVAL);
160 	}
161 	if ((((uintptr_t)pa) % PAGE_SIZE) != 0) {
162 		printf("address not page aligned %#lx\n", (uintptr_t)pa);
163 		return (EINVAL);
164 	}
165 	if (ptr != NULL) {
166 		/*
167 		 * If we're doing a virtual dump, flush any
168 		 * pre-existing pa pages.
169 		 */
170 		error = blk_flush(di);
171 		if (error != 0)
172 			return (error);
173 	}
174 	while (sz) {
175 		len = maxdumpsz - fragsz;
176 		if (len > sz)
177 			len = sz;
178 		counter += len;
179 		progress -= len;
180 		if (counter >> 22) {
181 			report_progress(progress, dumpsize);
182 			counter &= (1 << 22) - 1;
183 		}
184 
185 		wdog_kern_pat(WD_LASTVAL);
186 
187 		if (ptr) {
188 			error = dump_append(di, ptr, 0, len);
189 			if (error != 0)
190 				return (error);
191 			ptr += len;
192 			sz -= len;
193 		} else {
194 			dump_va = (void *)PHYS_TO_DMAP(pa);
195 			fragsz += len;
196 			pa += len;
197 			sz -= len;
198 			error = blk_flush(di);
199 			if (error != 0)
200 				return (error);
201 		}
202 
203 		/* Check for user abort */
204 		c = cncheckc();
205 		if (c == 0x03)
206 			return (ECANCELED);
207 		if (c != -1)
208 			printf(" (CTRL-C to abort) ");
209 	}
210 
211 	return (0);
212 }
213 
214 int
215 minidumpsys(struct dumperinfo *di)
216 {
217 	pd_entry_t *l1, *l2;
218 	pt_entry_t *l3;
219 	struct minidumphdr mdhdr;
220 	uint32_t pmapsize;
221 	vm_offset_t va;
222 	vm_paddr_t pa;
223 	int error;
224 	uint64_t bits;
225 	int i, bit;
226 	int retry_count;
227 
228 	retry_count = 0;
229 retry:
230 	retry_count++;
231 	error = 0;
232 	pmapsize = 0;
233 
234 	/* Build set of dumpable pages from kernel pmap */
235 	for (va = VM_MIN_KERNEL_ADDRESS; va < kernel_vm_end; va += L2_SIZE) {
236 		pmapsize += PAGE_SIZE;
237 		if (!pmap_get_tables(pmap_kernel(), va, &l1, &l2, &l3))
238 			continue;
239 
240 		/* We should always be using the l2 table for kvm */
241 		if (l2 == NULL)
242 			continue;
243 
244 		/* l2 may be a superpage */
245 		if ((*l2 & PTE_RWX) != 0) {
246 			pa = (*l2 >> PTE_PPN1_S) << L2_SHIFT;
247 			for (i = 0; i < Ln_ENTRIES; i++, pa += PAGE_SIZE) {
248 				if (is_dumpable(pa))
249 					dump_add_page(pa);
250 			}
251 		} else {
252 			for (i = 0; i < Ln_ENTRIES; i++) {
253 				if ((l3[i] & PTE_V) == 0)
254 					continue;
255 				pa = (l3[i] >> PTE_PPN0_S) * PAGE_SIZE;
256 				if (is_dumpable(pa))
257 					dump_add_page(pa);
258 			}
259 		}
260 	}
261 
262 	/* Calculate dump size */
263 	dumpsize = pmapsize;
264 	dumpsize += round_page(msgbufp->msg_size);
265 	dumpsize += round_page(vm_page_dump_size);
266 	for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
267 		bits = vm_page_dump[i];
268 		while (bits) {
269 			bit = ffsl(bits) - 1;
270 			pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) +
271 			    bit) * PAGE_SIZE;
272 			/* Clear out undumpable pages now if needed */
273 			if (is_dumpable(pa))
274 				dumpsize += PAGE_SIZE;
275 			else
276 				dump_drop_page(pa);
277 			bits &= ~(1ul << bit);
278 		}
279 	}
280 	dumpsize += PAGE_SIZE;
281 
282 	progress = dumpsize;
283 
284 	/* Initialize mdhdr */
285 	bzero(&mdhdr, sizeof(mdhdr));
286 	strcpy(mdhdr.magic, MINIDUMP_MAGIC);
287 	mdhdr.version = MINIDUMP_VERSION;
288 	mdhdr.msgbufsize = msgbufp->msg_size;
289 	mdhdr.bitmapsize = vm_page_dump_size;
290 	mdhdr.pmapsize = pmapsize;
291 	mdhdr.kernbase = KERNBASE;
292 	mdhdr.dmapphys = DMAP_MIN_PHYSADDR;
293 	mdhdr.dmapbase = DMAP_MIN_ADDRESS;
294 	mdhdr.dmapend = DMAP_MAX_ADDRESS;
295 
296 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_RISCV_VERSION,
297 	    dumpsize);
298 
299 	error = dump_start(di, &kdh);
300 	if (error != 0)
301 		goto fail;
302 
303 	printf("Dumping %llu out of %ju MB:", (long long)dumpsize >> 20,
304 	    ptoa((uintmax_t)physmem) / 1048576);
305 
306 	/* Dump minidump header */
307 	bzero(&tmpbuffer, sizeof(tmpbuffer));
308 	bcopy(&mdhdr, &tmpbuffer, sizeof(mdhdr));
309 	error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
310 	if (error)
311 		goto fail;
312 
313 	/* Dump msgbuf up front */
314 	error = blk_write(di, (char *)msgbufp->msg_ptr, 0,
315 	    round_page(msgbufp->msg_size));
316 	if (error)
317 		goto fail;
318 
319 	/* Dump bitmap */
320 	error = blk_write(di, (char *)vm_page_dump, 0,
321 	    round_page(vm_page_dump_size));
322 	if (error)
323 		goto fail;
324 
325 	/* Dump kernel page directory pages */
326 	bzero(&tmpbuffer, sizeof(tmpbuffer));
327 	for (va = VM_MIN_KERNEL_ADDRESS; va < kernel_vm_end; va += L2_SIZE) {
328 		if (!pmap_get_tables(pmap_kernel(), va, &l1, &l2, &l3)) {
329 			/* We always write a page, even if it is zero */
330 			error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
331 			if (error)
332 				goto fail;
333 			/* Flush, in case we reuse tmpbuffer in the same block */
334 			error = blk_flush(di);
335 			if (error)
336 				goto fail;
337 		} else if ((*l2 & PTE_RWX) != 0) {
338 			/* Generate fake l3 entries based on the l2 superpage */
339 			for (i = 0; i < Ln_ENTRIES; i++) {
340 				tmpbuffer[i] = (*l2 | (i << PTE_PPN0_S));
341 			}
342 			/* We always write a page, even if it is zero */
343 			error = blk_write(di, (char *)&tmpbuffer, 0, PAGE_SIZE);
344 			if (error)
345 				goto fail;
346 			/* Flush, in case we reuse tmpbuffer in the same block */
347 			error = blk_flush(di);
348 			if (error)
349 				goto fail;
350 			bzero(&tmpbuffer, sizeof(tmpbuffer));
351 		} else {
352 			pa = (*l2 >> PTE_PPN0_S) * PAGE_SIZE;
353 
354 			/* We always write a page, even if it is zero */
355 			error = blk_write(di, NULL, pa, PAGE_SIZE);
356 			if (error)
357 				goto fail;
358 		}
359 	}
360 
361 	/* Dump memory chunks */
362 	/* XXX cluster it up and use blk_dump() */
363 	for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
364 		bits = vm_page_dump[i];
365 		while (bits) {
366 			bit = ffsl(bits) - 1;
367 			pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) +
368 			    bit) * PAGE_SIZE;
369 			error = blk_write(di, 0, pa, PAGE_SIZE);
370 			if (error)
371 				goto fail;
372 			bits &= ~(1ul << bit);
373 		}
374 	}
375 
376 	error = blk_flush(di);
377 	if (error)
378 		goto fail;
379 
380 	error = dump_finish(di, &kdh);
381 	if (error != 0)
382 		goto fail;
383 
384 	printf("\nDump complete\n");
385 	return (0);
386 
387 fail:
388 	if (error < 0)
389 		error = -error;
390 
391 	printf("\n");
392 	if (error == ENOSPC) {
393 		printf("Dump map grown while dumping. ");
394 		if (retry_count < 5) {
395 			printf("Retrying...\n");
396 			goto retry;
397 		}
398 		printf("Dump failed.\n");
399 	}
400 	else if (error == ECANCELED)
401 		printf("Dump aborted\n");
402 	else if (error == E2BIG) {
403 		printf("Dump failed. Partition too small (about %lluMB were "
404 		    "needed this time).\n", (long long)dumpsize >> 20);
405 	} else
406 		printf("** DUMP FAILED (ERROR %d) **\n", error);
407 	return (error);
408 }
409 
410 /*
411  * Add a page to the minidump bitmap.
412  */
413 void
414 dump_add_page(vm_paddr_t pa)
415 {
416 	int idx, bit;
417 
418 	pa >>= PAGE_SHIFT;
419 	idx = pa >> 6;		/* 2^6 = 64 */
420 	bit = pa & 63;
421 	atomic_set_long(&vm_page_dump[idx], 1ul << bit);
422 }
423 
424 /*
425  * Remove page from the minidump bitmap.
426  */
427 void
428 dump_drop_page(vm_paddr_t pa)
429 {
430 	int idx, bit;
431 
432 	pa >>= PAGE_SHIFT;
433 	idx = pa >> 6;		/* 2^6 = 64 */
434 	bit = pa & 63;
435 	atomic_clear_long(&vm_page_dump[idx], 1ul << bit);
436 }
437